The conservative Koch political network is coming out hard against the Trump administration’s plan to step up enforcement of the nation’s cannabis laws, joining a growing group on the political right who are urging the president to push back against drug war hardliners like Attorney General Jeff Sessions.

“You are never going to win the war on drugs. Drugs won,” Mark Holden, one of the influential network’s top leaders, told reporters in Colorado Springs, according to the Denver Post. His statements came as the network opened a three-day retreat at The Broadmoor resort in Colorado Springs.

In Denver Post reporter John Frank’s story Sunday, Holden, the general counsel for Koch Industries—the second-largest privately owned company in the US—said the network has disagreed with Sessions’s decision to re-evaluate a federal policy not to interfere in state medical marijuana systems and taken issue with the attorney general’s request that Congress lift restrictions to allow the justice department to crack down on state-legal medical programs. He said Sessions’ stance represented a “failed big government top-down approach,” adding that “we should let the states decide.”

In a letter sent in May and made public earlier this month, Sessions urged Congress to roll back a protection known as the Rohrabacher-Blumenauer amendment, which prohibits the Justice Department from using federal funds to prevent certain states “from implementing their own state laws that authorize the use, distribution, possession, or cultivation of medical marijuana.” The rule has stymied at least one high-profile case against a California cannabis business.

Charles and David Koch have spent millions to further their conservative political goals. Some of those aims overlap with policies supported by liberals. Holden, for example, is currently in charge of a network-backed effort to address overcriminalization and criminal justice reform.

Earlier this month, another conservative voice—longtime Trump confidant Roger Stone—came out in opposition to the administration’s threatening stance toward state-legal cannabis. In an interview with Leafly last week, Stone called Sessions “a Southern conservative hard-core right-wing drug warrior who has probably never smelled marijuana in his life and has probably seen the movie ‘Reefer Madness’ a hundred times.”

Stone filed paperwork last week with the Internal Revenue Service to create the United States Cannabis Coalition, a nonprofit political organization with the same tax-exempt status as super-PACs that influence politicians and elections.